1. Field of the Invention
The present invention relates to a semiconductor device having an organic material substrate as a member, and particularly to a semiconductor device on both sides of whose organic material substrate a semiconductor chip and a semiconductor package are respectively mounted.
2. Description of the Related Art
As one aspect of a semiconductor device (semiconductor package), there is a semiconductor device using a substrate of an organic material such as a glass epoxy resin as a substrate of a package, to almost a center of one surface of which a semiconductor chip is flip chip connected while on the other surface of which another semiconductor package such as a LGA (land grid array) is secondarily mounted. Such an aspect is one of semiconductor packages called Package-on-Package (PoP).
A solder joint portion of the substrate surface on which the other semiconductor package is secondarily mounted is called a secondary mounting portion. In the PoP, reliability of the secondary mounting portion depends on many elements such as, and a cross relationship of: a standoff, size, material, and thickness of the secondarily mounted package; presence/absence of an underfill resin under the secondarily mounted package, and a material thereof; a material, size, thickness of a substrate of the PoP side; and size, position, thickness and the like of a semiconductor chip which is flip chip mounted on the one surface of the substrate.
The reliability of the secondary mounting portion is generally enhanced by providing the underfill resin between the secondarily mounted package and the substrate of the PoP side under the secondarily mounted package. Also, connecting the secondarily mounted package and the PoP side substrate via a solder ball is generally effective in enhancing the reliability. It is because stress occurring to the secondary mounting portion becomes small by the solder being provided therein so that the standoff of the secondarily mounted package becomes large. However, in the former, addition of the underfill resin leads to an increase in process steps and a high cost, and in the latter, due to an increase in a height as a PoP package, there is a problem when a thin package is required in such a case of application to a cellular phone and the like.
Incidentally, as examples of the PoP, there are semiconductor devices disclosed in Japanese Patent Laid-open Application No. 2004-15068 and in International Publication No. WO 01/026155 pamphlet, though constitutions thereof are different from that of the semiconductor device according to the present invention.
[Patent Document 1] Japanese Patent Laid-open Application No. 2004-15068
[Patent Document 2] International Publication No. WO 01/026155 pamphlet